Tumour response in metastatic renal cell carcinoma treated with tyrosine kinase inhibitors - assessment of intra-tumour heterogeneity

Intra-tumour heterogeneity is a common molecular phenomenon in metastatic clear cell renal carcinoma (mRCC), representing the genetic complexity of a tumour with multiple metastatic sites. The present commentary discusses the observed phenomena of phenotypic intra-tumour heterogeneity in mRCC patients treated with the tyrosine kinase inhibitors sunitinib or pazopanib. Here, drug response can be different on the level of each evaluated metastasis in the individual patient. This questions the currently used radiologic staging systems of RECIST criteria and demands for a modification of radiologic response assessment with the consequence of a patient-tailored therapy in the clinical setting.Please see related article: http://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-016-0729-9 .

Survival of patients with clear cell renal carcinoma according to number and location of organ-specific metastatic sites

BACKGROUND

The prognostic significance of number and location of organ-specific metastatic sites in treated metastatic clear cell renal carcinoma (ccmRCC) patients is object of debate. The current study aimed to test the association between number and location of organ-specific metastatic sites and overall survival (OS) in ccmRCC.

MATERIALS AND METHODS

Within Surveillance, Epidemiology and End Results database (2010-2018), all ccmRCC patients treated with cytoreductive nephrectomy and/or systemic therapy were identified. Kaplan-Meier plots and Cox regression models focused on: A). number of organ-specific metastatic sites: solitary vs. 2 vs. 3 or more; B). solitary organ-specific metastatic sites (lung vs. bone vs. liver vs. brain); C). combinations of 2 and 3 or more different organ-specific metastatic sites.

RESULTS

Of 4,527 patients (median OS: 19 months), 3,054 (67%) harbored solitary organ-specific metastatic sites (27 months) vs. 1,153 (25%) combinations of 2 different organ-specific metastatic sites (12 months) vs. 320 (8%) combinations of 3 or more different organ-specific metastatic sites (7 months). In patients with solitary organ-specific metastatic sites, bone metastases portended the longest median OS (median OS: 31 months) vs. liver metastases portended the shortest median OS (16 months). Both were independent predictors of OS (multivariable hazard ratio, bone: 0.87; liver: 1.21). Median OS was similarly poor in patients with combinations of 2 different organ-specific metastatic sites (9-13 months), regardless of their location. The same pattern applied to patients with combinations of 3 or more different organ-specific metastatic sites (6-7 months).

CONCLUSIONS

Solitary organ-specific metastatic sites portend the most favorable OS (16-31 months). Solitary bone metastases yield the longest vs. liver metastases the shortest OS. Invariably poor OS applies to combinations of 2 (9-13 months), as well as 3 or more different organ-specific metastatic sites (6-7 months), regardless of their location.